Renewable cartridge fuse



April 22, 1947. E RBR S 2,419,250

RENEWABLE CARTRIDGE FUSE Filed Jan. 18, 1945 2 Sheets-Sheet l gag! e- .62 Z25 4:2; I E 4: g 20 A 1 40 J12 i139 32- 52 Q \i l m 0/ 54 24 j 3 20 Z? j i 40 52 26 -INVENTOR. 0 BY f g/e 574/5 g $24? m xi ATTOEN K April 22, 1947. E, P, BRUS 2,419,250

RENEWABLE CARTRIDGE FUSE Filed Jan. 18, 1945 2 Sheets-Sheet 2 T INVENTOR. 66 Em/VQ 5/4/5 Fi 9. BY Q A TTOP/VE Y.

Patented Apr. 22, 1947 UNITED STATES PATENT OFFICE RENEWABLE CARTRIDGE FUSE Emile P. Brus, Kansas City, Mo,

Application January 18, 1943, Serial No. 472,655

This invention relates to fuses and. more particularly, to renewable cartridge fuses of the ferrule type.

An important aim of the instant invention is the provision of a fuse having means embodied therein for effecting a positive contact of the fuse link ends with the end caps or ferrules of the fuse to insure free how of current through the fuse assembly.

A further aim of this invention is the provision of a fuse having a link of simple, low cost construction, which can be easily inserted in the fuse cartridge and attached to the end caps with a minimum amount of eifort.

It is a further object of the invention to provide a fuse cartridg having as a part thereof, an inexpensive yet reliable indicator to enable an inspector to ascertain the condition of the fuse at a glance.

Other objects will appear during the course of the following specification, referring to the accompanying drawings wherein:

Fig. 1 is a side elevational view of a preferred form of fuse constructed in accordance with this invention.

Fig. 2 is a longitudinal central section through the fuse body and link.

Fig. 3 is a cross section taken on line III-III of Fig. 2.

Fig. 4 is a side elevational view of the fusible link stretched out and removed from operative position.

Fig. 5 is an edge elevational View of the same.

Fig, 6 is an enlarged fragmentary sectional view of the fuse illustrating in particular the form of threads used for securing an end cap to the fuse body.

Fig. '7 is a side elevational view of a fuse made to embody a modified form of the invention, with one end cap shown in section.

Fig. 8 is a longitudinal central sectional view through the fuse assembly.

Fig. 9 is an end elevational view of the fuse shown in Fig. 7 with the end cap removed.

Fig. 10 is a fragmentary stretched out perspective view of one end of the fuse body with the nut and attached link removed from the notches.

Fig. 11 is a side elevational view of a fuse embodying a further modified form of the invention, with both end caps shown in section; and

Fig. 12 is a fragmentary view in perspective of one notched end of the type of fuse body shown in Fig. 11, with the nut and attached link removed from the notches.

11 Claims. (01. 200- 131) In the drawings the numeral 20 designates a tubular fuse body of non-conducting material formed of transparent, translucent or opaque material.

The body 20 is partially closed at each end by a wall 22 having a receding inner face 24 and a recess 26 in its outer face. A link 28 of fusible material may be notched at its approximate center to form necks 30 thereby setting off a central section 32, which drops from the remainder of the link when a current of excessive intensity melts the reduced necks.

Formed on each end of link 28 is a boss 34 preferably comprising a perforated, internally threaded boss or nut soldered or otherwise secured to the link with the screw-threaded perforation 36 registering with an opening 38 in the link 28.

As clearly shown in Fig. 2, bosses 34 are fixed to opposite faces of the link at the extreme ends thereof and are adapted to seat in the recesses 25 of end walls 22 after the link is extended through the tubular bodyin a diagonal direction and its end portions are bent laterally into recesses 26 respectively. It is obvious that the inclination of faces 24 of end walls 22 facilitate proper threading of the link 28 and attached nuts through the tubular body of the fuse.

A cap or ferrule 48 having a central aperture 42 in register with perforation 36 and opening 38 is provided for each end of fuse body 20, and is secured thereto by internal threads 44 engaging external threads 46 of the body 20. It is desirable that threads 46 be deep and sharp and that threads 44 be shallow and arcuate in cross section or vice verse. to produce a circuitous passageway for the escape of gases created when. the fuse blows.

The ends of fuse link 28 are forced to intimate contact with the inner faces of their respective end caps 45) by screws 48 that extend through apertures 42 and openings 38 in the caps and link respectively, and threaded into perforations 36 of bosses 34. In some instances it may be found desirable to use a modified form of screw 49 for attaching a conductor 5| to the cap 40,

A visual indicator for denoting the condition of the fuse comprises a button 59 extending laterally through an opening in the fuse body 20 and having a stop 52 on its outer end and an impact-receiving head 54 on its inner end. In a blown fuse the indicator button will assume the position shown in dotted lines in Fig. 2, and

its movement through the opening in the wall of body 20 should be sufficiently restricted to insure that its position will not be altered by anything less than a manual pressure from the outside or an impact generated from the inside by the blowing of the fuse.

In the modification illustrated in Figs. 7 to 10 inclusive, a somewhat simpler type of cartridge fuse is provided, comprising a tubular body having diametrically opposed notches 62 in each end for seating an elongated boss or nut 64. Each nut 64 has a central screw-threaded perforation 66 and a slot 68. A fusible link 10 having each end portion threaded through slot 63 of its respective nut is preferably soldered or otherwise secured to the nut and provided with an opening 72 in alignment with perforation 88.

An end cap 14 in screw-threaded engagement with each end of body 60 has a countersunk aper ture 16 for receiving a screw 18 serving to draw the link 19 tightly against the inner face of the end cap.

Figs, 11 and 12 illustrate a further modified form of cartridge fuse wherein the tubular body 80 is provided with end notches 82 having undercut portions 84. A fuse link 88 and attached bosses or nuts 88 is identical to that shown in the form illustrated in Figs. 7 to 10 inclusive.

It will be observed from Fig. 12 that the formation of notches 82 is such as to permit insertion therein of nuts 88 which may then be slightly turned to engage the undercut portions 84, whereupon a straight outward movement of the nut from the fuse body becomes impossible.

End caps or ferrules 90 do not therefore. need screw-threaded engagement with the fuse body. as in the case of the forms previously described. These caps are, however, provided with countersunk apertures 92 and screws 94 extended there through are'threaded into nuts 88. Threaded engagement of screws 94 with nuts 83 should be relatively tight to cause immediate turning movement of the nut for seating the same within the undercut portion of notches 82. Continued threading of screw 94 in nut 88 will securely anchor th respective end cap to the fuse body.

From the foregoing, it will be apparent that the objects of this invention have been accomplished and while it is conceivable that other modifications might be made without departing from the spirit of this invention, it is desired to be limited only by the scope of the appended claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

l. A renewable fuse of the character described comprising a tubular body of non-conducting material having integral Walls partially closing the ends thereof; a fuse link extending through the body; bosses on the ends of the link, said bosses and the end walls of the tubular body having inter-engaging means to prevent rotative movement of the bosses independently of the body. said bosses having screw-threaded perforations on the axis of the tubular body; a cap of conducting material removably mounted on each end of the body having an opening in registry with the perforation in an adjacent boss; and screws extended through said caps and threaded into said bosses.

2. A renewable fuse of the character described comprising a tubular body of non-conducting material having end walls provided with recesses in their outer faces and on the axis of the tubular body, a fuse link extending through the body; bosses on the ends of the link for seating in said recesses, said bosses having screw-threaded perforations; a cap of conducting material removably mounted on each end of the body having an opening in registry with the perforation in an adjacent boss; and screws extended through said caps and threaded into said bosses, the end Dortions of said link being between the bosses and said caps when in the operative position.

3. A renewable fuse of the character described comprising a tubular body of non-conducting material provided with integral walls partially closing the ends of the body; a cap of conducting material removably mounted on each end respectively of the body; and a fuse link extending through the body and joined to the caps.

4. A renewable fuse of the character described comprising a, tubular body of non-conducting material provided with integral walls partially closing the ends of the body; a cap of conducting material removably mounted on each end respectively oi the body; and a fuse link extending through the body and joined to the caps, said Walls each having an inclined face therein extending downwardly and inwardly from the respective ends of the body to guide the fuse link toward the mouth of the body when the same is moved to place.

5. A renewable fuse of the character described comprising a tubular body of non-conducting material provided with integral walls partially closing the ends of the body; a cap of conducting material removably mounted on each end respectively of the body; and a fuse link extending through the body and joined to the caps, the said walls being substantially diametrically opposed to present offset mouths at the ends of the body.

A renewable fuse of the character described, comprising a tubular body of non-conducting material provided with integral walls partially closing the ends of the body; a cap of conducting material removably mounted on each end respectively of the body; and a fuse link extending through the body and joined to the caps, each of said walls having a socket formed in the outer face thereof, the ends of said fuse link being disposed within the sockets when joined to the caps.

'7. A renewable fuse of the character described comprising a tubular body of non-conducting material provided with integral walls partially closing the ends of the body; a cap of conducting material removably mounted on each end respectively of the body; and a fuse link extending through the body and joined to the caps, each of said walls having a ocket formed in the outer face thereof, the ends of said fuse link having a boss thereon disposed within the sockets respectively when the link is joined to the caps.

8. A renewable fuse of the character described comprising a tubular body of non-conducting material provided with walls partially closing the ends of the body; a cap of conducting material removably mounted on each end respectively of the body; and a fuse link extending through the body and joined to the caps, each of said walls aving a socket formed in the outer face thereof, the ends of said fuse link having a boss thereon disposed within the sockets respectively when the link is joined to the caps, each boss being provided with a threaded perforation therethrough, each cap having a screw extending therethrough into threaded engagement with the proximal boss.

9. A renewable fuse of the character described comprising a tubular body of non-conducting material provided with walls partially closing the ends of the body; a cap of conducting material removably mounted on each end respectively of the body; a fuse link extending through the body and joined to the caps; and a freely shiftable signal button extending through the wall of said tubular body.

10. A renewable fuse of the character described comprising a tubular body of non-conducting material provided with walls partially closing the ends of the body; a cap of conducting material removably mounted on each end respectively of the body; a fuse link extending through the body and joined to the caps; and a freely shiftable signal button extending through the wall of said tubular body, said fuse link having a notch there in to present a length thereof of reduced crosssectional area, said signal button being adjacent to said area.

11. A renewable fuse of the character described comprising a tubular body of non-conducting material provided with Walls partially closing the ends of the body; a cap of conducting material removably mounted on each end respectively of the body; a fuse link extending through the body and joined to the caps; and a freely shiftable signal button extending through the wall of said tubular body, said fuse link having a notch therein to present a length thereof of reduced crosssectional area, said signal button being adjacent to said area, said signal button having a shank slidably mounted in the wall of the body for longitudinal movement and a head on the inner end of said shank presenting an impact-receiving surface.

EMILE P. BRUS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,762,607 Boll June 10, 1930 1,881,369 Carney Oct. 4, 1932 1,354,284 Cooley Sept. 28, 1920 Re. 14,239 Daum Jan, 2, 1917 782,038 Lockwood et al 1- Feb. 7, 1905 1,436,919 Smith Nov. 28, 1922 1,542,822 Chandler June 23, 1925 1,798,174 Sheller Mar, 31, 1931 2,271,729 Baldwin et a1 Feb. 3, 1942 1,378,136 Rosenthal et al May 17, 1921 1,387,000 Fisher Aug, 9, 1921 1,400,660 Cole Dec, 20, 1921 1,231,036 McDonald June 26, 1917 

